A passage, especially the passage between the third and fourth ventricles in the brain; the aqueduct.
{{quote-text|en|year=1916|author=Mayo Clinic|title=Collected Papers of the Mayo Clinic and the Mayo Foundation|page=869
procedure, course
(syn)
a route, ''whether:''
a journey, trip
a march
a course
a path; a road
a court circuit
a passage
(tr-verb form of)